Printing plate assembly



P 1969 a. 1.. WATERHOUSE ETAL 3,468,253-

PRINTING PLATE ASSEMBLY Filed Jan. 9. 1967 fimcel. Zl/aragme, v

fredMJern/t, m EdIl/JWEMQZZO? 4 V ite U.S. Cl. 101-395 6 Claims ABSTRACT OF THE DISCLOSURE A printing plate assembly defined by a rigid perforated saddle component and a body component of thermoplastic material having preformed integral projections fitting into the perforations of the saddle component for attaching the body component to the saddle component.

The present invention relates to a printing plate assembly having utility for making a printing plate and mounting the same on printing apparatus.

It has been the practice for many years in stereotype printing to provide a printing plate by casting molten lead into a matrix. The resulting plate is heavy and the press for using such plates must be of rugged and strong construction to run such plates and provide for any substantial production of printed material. Additionally, to reuse the lead for subsequent plates requires expensive equipment and the methods employed with such equipment are slow and cumbersome.

In view of the foregoing, the art has experimented with other materials for fabricating printing plates such as by using plastic compositions, both thermoplastic and thermosetting. Such practices in the art have not been fully practical due, in some instances, to the inability of using the plastic compositions for making a plurality of successive and different useful printing plates, and in other cases of inconvenience in maintaining dimensional stability of the plates for effecting satisfactory registration of printed material.

In order to overcome some of the last noted objections it is known to provide a plastic printing plate by providing a preform component from which a printing plate may be made embodying a mesh reinforcing com ponent embedded in the body component of thermoplastic material and in which the mesh reinforcing component is intended to impart stability in the lengthwise and crosswise directions of the preform, and also serve as a reservoir means for displacement of the thermoplastic material in forming a printing surface.

The approach last noted is somewhat unsatisfactory from a practical standpoint in that the crossing wires of the wire mesh reinforcing may readily shift with respect to each other from their desired lengthwise and crosswise positions altering the desired configuration of a printing plate to be formed from the assembly, and displace relative to the plastic body component unless meticulous care and attention is paid in forming the preform component into a printing plate. Further in the preform component noted a separate saddle or carrier member is required to mount the formed printing plate or printing apparatus.

It is the purpose of the present invention to overcome the aforementioned and other disadvantages of known plastic printing plates by providing a printing plate assembly comprising a rigid saddle component and a body component of thermoplastic material, and in which the saddle component has a plurality of perforations for receiving integral projections extending from a planar portion of the thermoplastic body component so that the rigid saddle component provides for the mounting of the States Patent M 3,468,253 Patented Sept. 23, I969 assembly in a printing apparatus, and with the perforations in the saddle component serving as reservoir means for displacement of the material of the projections in the formation of a printing surface on the planar portion of the body component.

The saddle component as aforementioned is rigid and imparts fixed lengthwise and transverse stability to the assembly and may be formed flat or curved for utilization in flat bed or rotary printing apparatus, and in this respect is of considerable advantage and utility over the aforementioned wire mesh reinforced preform component. The body component may conveniently comprise any suitable thermoplastic material such as low density polyethylene, polypropylene, polystyrene, polyvinyl chloride, ethylene, mixtures thereof or like equivalent plastic materials. The aforementioned projections of the body component fit into the perforations of the saddle with the perforations in the saddle serving as reservoir means for the displacement of the material of the projections relative to such perforations in the forming of printing characters on an outer surface of the planar portion of the body component.

A preferred feature of the invention resides in providing at least some of the perforations in the saddle and projections on the body component of formations to provide a snap or inter-locking fit therebetween to firmly secure the body component to the saddle member.

With an assembly as aforenoted, a printing plate may be readily fabricated by providing a saddle component, of either flat or curved configuration, and with which the body component of thermoplastic material is assembled therewith. The assembly thus formed may be positioned with the body component in superposed relation with respect to a matrix for the desired printing plate and between the platens of a press, and then displacing the plastic component by relative movement of the material of the projections with respect to the perforations of a saddle member into the indentations of the matrix. In the completed printing plate, the saddle component provides a rigid member for mounting of the plate on a printing apparatus and assures good registration of the printing indicia formed on the plastic body component.

The above and other objects and advantages of the invention will appear from the following detailed description of preferred embodiments of the invention.

In the drawings:

FIGURE 1 is a perspective view of a printing plate assembly of the present invention with the saddle component and plastic body component body thereof in spaced apart relation to show perforations of the saddle component and the projections of the body component fitting into the perforations of the saddle component;

FIGURE 2 is a detail cross sectional view through one perforation of a saddle component and one of the projections of a body component fitting into the perforation of the saddle component;

FIGURE 3 is a detail cross sectional view showing another form of configuration of perforation for a saddle component and a projection of a body component therefor;

FIGURE 4 is a detail cross sectional view showing still another configuration of a perforation for a saddle component and a projection of a body component therefor;

FIGURE 5 is a plan view of a portion of a printing plate assembly of the present invention;

FIGURE 6 is a detail vertical cross sectional view taken along the line 6-6 of FIGURE 5 looking in the direction indicated by the arrows;

FIGURE 7 is a cross sectional view of a printing plate formed from the printing plate assembly of FIGURE 6; and

FIGURE 8 is a diagrammatic view illustrating the manner in which the printing plate assembly of the present invention is formed into a printing plate.

Referring now to FIGURE 1, the printing plate assembly 9 of the present invention comprises a plastic body component indicated at 10, which may be composed of any suitable or desirable thermoplastic material, such as low density polyethylene, or other types thereof, and further may comprise polypropylene, polystyrene, polyvinyl chloride, ethylene, mixtures thereof or like equivalent plastic compositions. The printing plate assembly 9 further comprises a saddle component as indicated generally at 11. The saddle component 11 is preferably fabricated of a rigid and substantially inextensible material such as metal or plastic to provide a dimensionally stable printing assembly. Light Weight metal, such as aluminum serves admirably well for the saddle component. The saddle component 11 may be of flat planar configuration for use in flat bed printing or may be of substantially semicylindrical form as shown in FIGURE 1, for mounting on the rotating drum of a rotary printing press.

The plastic body component is defined by a planar portion 12 having an outer surface 13 which is to be formed into a printing surface and from which planar portion 12 a plurality of integral preformed projections, indicated at 14, extend away from the outer surface of the planar portion. The saddle component 11 is formed with a plurality of preformed perforations, as at 15, each of a shape and configuration to receive one each of the projections 14 for mounting the body component on the saddle component of the printing plate assembly.

The cross-sectional configurations of the perforations 15 and projections 14 may vary widely to provide, as will be described below, for at least certain of them serving to secure the plastic body component 10 t0 the saddle member 11, and in which the same or other of the perforations 15 define reservoir means for the relative displacement therein of portions of the projections 14 and of the thermoplastic body component 10 in defining printing indicia at the outer surface 13 of the planar portion 12 of the body component.

In FIGURE 2 there is shown a portion of a saddle component 16 and a perforation 17 thereof and together with a projection 18 of a plastic body component member 19 in which the perforation 17 and the projection 18 each have matched portions of different transverse dimensions in which the projections 18 and the perforations 17 of the saddle member 16 provide for attaching the body component to the saddle component by pressing or snapping the projections 18 into the perforations 17. The transverse configurations of the perforation 17 and the projection 18 in the illustrated embodiment engage in an interlocking relationship upon forcing of the displaceable free ends of the projections 18 through the perforations 17 in the saddle member 16.

Referring now to FIGURE 3 there is shown a modified form of perforation 23 of a saddle component 24 and a projection 25 of a body component 26 therefor in which the perforation 23 and the projection 25 are substantially circular in cross-section with the projection being preferably slightly larger than the perforation to provide a tight friction fit between the projection and wall of the perforation.

Turning now to FIGURE 4 there is shown a portion of still another saddle member 30 formed with a tapered perforation 32 into which a correspondingly tapered projection 33 of the body component 34 extends. The projection 33 and perforation 32 taper in a direction so that the ends of smaller dimension lie away from the planar portion 35 of the body component 34.

It will be readily understood that many configurations in addition to those above described may be provided for the perforations in the saddle component and the projections of the plastic body component, and such perforations and projections may provide for interlocking of the components with each other or for a friction fit between the projections and perforations. Any number of perforations and projections may be provided to secure the plastic body component to the saddle component and these same perforations and/ or other perforations of the saddle component serve as reservoir means for the projections of the body component so that the material of a projection may be displaced relative to the perforation in the saddle component to provide printing indicia at the outer surface of the planar portion of a plastic body component as will be below described.

Upon reference now to FIGURES 5 and 6, there is shown a printing plate assembly 36 embodying the body component 34 and saddle component 30 as last described in connection with FIGURE 4. As previously indicated, at least some or all of the projections 33 of the body component and the perforations 32 of the saddle member therefore may provide for the mounting of the body component 34 on the saddle component 30, and certain or all of the perforations 32 as may be desired, define reservoir means for the material or projections 33 of the body component so that the material of the projections may displace relative to the perforations 32 in the formation of printing indicia at the outer surface 37 of the planar portion 35 of the body component 34.

In forming a printing plate, such as shown in FIGURE 7, from the above described saddle member and plastic body component, the printing plate assembly 36 may be positioned, as shown in FIGURE 8, between any suitable and conventional matrix 41 and a lower platen 42 of a configuration conforming to that of the printing plate assembly 36. An upper platen 43 having a surface conforming to that of the planar portion 35 of the printing plate assembly 36 is disposed above the matrix. Thereafter the lower and upper platens 42 and 43 are brought together. Air between the printing plate assembly 36 and the matrix 41 may be removed by vacuum and heat and slight pressure may be applied to effect softening of the plastic body component so that the outer surface of the planar portion 37 of the body component 34 is displaced into the recesses of the matrix 41 to provide printing indicia as at 47. Alternatively, the body component may be heated to render it displaceable into the recesses of the matrix by pressure applied by the platens.

As diagrammatically illustrated in FIGURE 7, it will be seen that the material of the projections 33 of the body component 34 have been displaced to provide the printing indicia indicated generally at 47. The saddle component 30 is rigid and in forming of the printing indicia at the outer surface of the planar portion of the body component, voids are formed at the base of the saddle component corresponding to the extent that the plastic material of the projections and of the body component have been displaced in forming the printing indicia of the printing plate. Thus, the perforations 32 serve as reservoir means providing for the relative movement of the material of the body component in forming the printing plate. The saddle member 30 since it is rigid and dimensionally stable remains stationary and the material of the body component moves relative to the saddle component.

If desired and to facilitate formation of printing indicia on the plastic body component the latter may be preheated before it is positioned between the platens 42 and 43.

The invention claimed is:

l. A printing plate assembly comprising a rigid saddle component formed with a plurality of preformed perforations extending between inner and outer surfaces thereof, and a body component of thermoplastic material, said body component being defined by a planar portion having an outer surface and a plurality of integral preformed projections extending away from said planar portion, said projections of said body component being disposed in the perforations of said saddle component and with said planar portion supported on said outer surface of said saddle component, and at least some of said perforations of said saddle component serving as reservoir means for said projections of said body component in said last named perforations for displacement of the material thereof relative to said last named perforations in the formation of a printing surface on said outer surface of said planar portion of said body component.

2. The printing plate assembly of claim 1 characterized by certain of said perforations and said projections thereof being formed to provide for attaching said body component to said saddle component by pressing said projections of said body component into the perforations of said saddle component.

3. The printing plate assembly of claim 1 characterized by at least certain of said perforations of said saddle component having transverse cross sectional portions thereof of different dimensions, and said projections in said last named perforations being of configurations corresponding to the configurations of said last named perforations.

4. A printing plate assembly comprising a rigid saddle component formed with a plurality of preformed perforations extending between inner and outer surfaces thereof, and a body component of thermoplastic material disposed in superposed relation with respect to said saddle component, printing indicia at the outer surface of said body component, said body component comprising a plurality of preformed projections extending from said body component in a direction away from said outer surface, said projections of said body component being disposed in the perforations of said saddle component, and at least some of said projections having portions thereof displaced relative to said perforations of said body component for forming said printing indicia.

5. A printing plate assembly of claim 4 characterized by certain of said perforations and said projections thereof being formed to provide for attaching said body component to said saddle component by pressing said last named projections of said body component into said last named perforations of said saddle component.

6. The printing plate of claim 4 characterized by at least certain of said perforations of said saddle component having transverse cross sectional portions thereof of different dimensions, and said projections in said last named perforations having transverse cross-sectional portions corresponding at least in part to the cross-sectional portions of said last named perforations to secure said body component to said saddle component.

References Cited UNITED STATES PATENTS 884,369 4/1908 De Wolf. 2,355,949 8/ 1944- Boutwell. 3,091,176 5/1963 Wall 10l395 ROBERT E. PULFREY, Primary Examiner J. REED FISHER, Assistant Examiner 

